1. Field of the Invention
The present invention relates generally to a balloon and, more particularly, to a sheet type balloon used as studying or playing materials.
2. Description of the Related Art
Conventional balloons are made chiefly of rubber or synthetic resin in the form of variously shaped, hollow bags inflated with air or gas, and generally used as playing materials, i.e., toys. However, conventional balloons are difficult to use for purposes related to coloring or studying because the surface of the balloon is not easily colored with crayons or paints after fabrication. The surface of the balloon is merely colored or printed during fabrication.
U.S. Pat. No. 5,108,339 has introduced a non-latex balloon, which includes a first inner balloon encompassed by a partially transparent second outer balloon. It is true that this balloon is a colorfully designed, interesting product, but such a toy balloon does not seem suited for coloring or studying materials.
Also, U.S. Pat. Nos. 5,108,339 and 5,482,492 have disclosed valves introducing an inflating gas into the balloon interior. However, these valves need additionally an inflation probe, such as a straw-like slender tube, so as to supply the filling fluid such as air into the valves. Therefore, such a valve and balloon assembly may cause inconvenience to a user, and furthermore, a user may be often hurt when he blows air carelessly into the inflation pipe with the inflation probe in his mouth. Moreover, since the above-discussed valves have structural limitations that a backward flow of an inflating gas is not allowed, the above balloons are not handy to carry with an inflating gas deflated. Unfortunately, this invites reuse issues and environmental pollution.